code: def ctrl(savefile="ctrl.png"):
      drawer = MPLDrawer(n_wires=2, n_layers=3)
  
      drawer.ctrl(layer=0, wires=0, wires_target=1)
      drawer.ctrl(layer=1, wires=(0, 1), control_values=[0, 1])
  
      options = {"color": "indigo", "linewidth": 4}
      drawer.ctrl(
          layer=2, wires=(0, 1), control_values=[1, 0], options=options
      )
  
      plt.savefig(folder / savefile)
      plt.close()
  
file_path: pennylane/doc/_static/drawer/mpldrawer_examples.py
imports: import pathlib
  import matplotlib.pyplot
  from pennylane.drawer import MPLDrawer
  from pennylane.drawer.style import _set_style
label_desc: Use image node_id 6 for calling a global function with example usage: ctrl(savefile) without return types